The equipment which we will purchase is an orthovoltage Siemens X-ray generator. This generator is critically needed for the accomplishment of our research in the field of biomedical and environmental research, particularly in the area of molecular genetics. Our present x-ray generators are 20-30 years old and are unreliable in performance and reproducible delivery of set doses. The purchase of a new generator will be of great help to us in our studies of the molecular mechanisms of radiation-induced injury which result in mutation, oncogenic transformation, and cell killing. In addition to investigators in the Department of Radiology, the generator will have impact on the research of scientists in the Departments of Medicine, Biochemistry, Environmental Health Sciences, Developmental Genetics and Anatomy, Physiology and Biophysics, and Pathology. Most of the faculty are members of the Case Western Reserve University Cancer Research Center, under whose auspices the maintenance and operation of the generator will be carried out, as a function of the Radiation Core Facility, under the direction of Dr. Oleinick. The overall objectives of the research involving the X ray generator are (1) to study the molecular processes comprising radiation-induced cellular damage and its modification by metabolic substances and DNA repair; (2) to investigate the processes involved in the expression of DNA damage; i.e., mutation, oncogenic transformation and lethality; and (3) to conduct genetic and molecular analyses of the genes involved in early development and oncogenesis.